SpaceX leases Launch Pad 39A from NASA and has modified the pad to support Falcon Heavy launches in 2017 and beyond.[3][4]NASA began modifying Launch Pad 39B in 2007 to accommodate the now defunct Project Constellation, and is currently preparing it for the Space Launch System[5][6] with first launch scheduled for 2018.[7] Pad C was originally planned but never built for Apollo, and would have been a copy of pads 39A and 39B. A smaller pad, designated 39C was constructed from January to June 2015 to accommodate small-class vehicles.[8]

NASA launches from LC-39A and 39B have been supervised from the NASA Launch Control Center (LCC), located 3 miles (4.8 km) from the launch pads. LC-39 is one of several launch sites that share radar and tracking services of the Eastern Test Range.

Northern Merritt Island was first developed around 1890 when a few wealthy Harvard University graduates purchased 18,000 acres (73 km2) and constructed a three-story mahogany clubhouse, very nearly on the site of Pad 39A.[9] During the 1920s, Peter E. Studebaker Jr., son of the automobile magnate, built a small casino at De Soto Beach eight miles (13 km) north of the Canaveral lighthouse.[10]

In 1948, the Navy transferred the former Banana River Naval Air Station located south of Cape Canaveral, to the Air Force for use in testing captured German V-2 rockets.[11] The site's location on the East Florida coast was ideal for this purpose in that launches would be over the ocean, away from populated areas. This site became the Joint Long Range Proving Ground in 1949, and was renamed Patrick Air Force Base in 1950. The Air Force annexed part of Cape Canaveral to the North in 1951, forming the Air Force Missile Test Center, the future Cape Canaveral Air Force Station (CCAFS). Missile and rocketry testing and development would take place here through the 1950s.[12]

In 1961, President Kennedy proposed to Congress the goal of landing a man on the Moon by the end of the decade. Congressional approval led to the launch of the Apollo program, which required a massive expansion of NASA operations, including an expansion of launch operations from the Cape to adjacent Merritt Island to the north and west.[14] NASA began acquisition of land in 1962, taking title to 131 square miles (340 km2) by outright purchase and negotiating with the state of Florida for an additional 87 square miles (230 km2). On July 1, 1962, the site was named the Launch Operations Center.[15]

At the time, the highest numbered launch pad on CCAFS was Launch Complex 37; when the lunar launch complex was designed, it was designated as Launch Complex 39. It was designed to handle launches of the Saturn V rocket, at the time the largest, most powerful rocket then designed, required to take Apollo to the Moon. Initial plans included four pads (five were considered) evenly spaced 8,700 feet (2,700 m) apart to avoid damage in the event of an explosion on the pad. Three were scheduled for construction (A-C, to the southeast) and two (D and E, west and north) would have been built at a later date. The numbering of the pads at the time was from north to south, with the northernmost being 39A, and the southernmost being 39C. Pad 39A was never built, and 39C became 39A in 1963. With today's numbering, 39C would have been north of 39B, and 39D would have been due west of 39C. Pad 39E would have been due north of the mid-distance between 39C and 39D, with 39E forming the top of a triangle, and equidistant from 39C and 39D. The Crawlerway was built with the additional pads in mind. This is the reason the Crawlerway turns as it heads to Pad B; continuing straight from that turn would have led to the additional pads.[16]

Apollo-Saturn 506 with Apollo 11 spacecraft being moved from the VAB to LC39A (1969)

A restored Crawler-Transporter (2004)

Months before launch, the three stages of the Saturn V launch vehicle and the components of the Apollo spacecraft were brought inside the Vehicle Assembly Building (VAB) and assembled in one of four high bays into a 363-foot (111 m)-tall space vehicle on one of three Mobile Launchers. Each mobile launcher consisted of a two-story, 161-by-135-foot (49 by 41 m) launch platform with four hold-down arms and a 446-foot (136 m) Launch Umbilical Tower (LUT) topped by a crane used to lift the spacecraft into position for assembly. The MLP and unfueled vehicle together weighed 12,600,000 pounds (5,715 t).[17]

The Umbilical Tower contained two elevators and nine retractable swing arms which extended to the space vehicle, to provide access to each of the three rocket stages and the spacecraft for people, wiring and plumbing while the vehicle was on the launch pad, and swung away from the vehicle at launch.[17][18] Technicians, engineers, and astronauts used the uppermost Spacecraft Access Arm to access the crew cabin. At the end of the arm, the white room provided an environmentally controlled and protected area for astronauts and their equipment to enter the spacecraft.[19]

When the stack integration was completed, it was moved the 3–4 miles (4.8–6.4 km) to the pad at a speed of 1 mile (1.6 km) per hour by one of two Crawler-Transporters. Each crawler weighed 6,000,000 pounds (2,720 t) and was capable of keeping the space vehicle on its Mobile Launcher level while negotiating a 5 percent grade to the pad. At the pad, the MLP was supported by six steel pedestals, plus four additional extensible columns.[17]

After the MLP was set in place, the Crawler-Transporter rolled a 410-foot (125 m), 10,490,000-pound (4,760 t) Mobile Service Structure (MSS) into place to provide further access for technicians to perform detailed checkout of the vehicle, and necessary umbillical connections to the pad. The MSS contained three elevators, two self-propelled platforms and three fixed platforms, and was rolled back 6,900 feet (2,100 m) to its parking position shortly before launch.[17]

A flame deflector was slid on rails into place under the launch pedestal. This system allowed for rotation with a second flame deflector, after the first was refurbished after each launch. Each deflector measured 39 feet (12 m) high by 49 feet (15 m) wide by 75 feet (23 m) long and weighed 1,400,000 pounds (635 t). It deflected the exhaust flame into a trench measuring 43 feet (13 m) deep by 59 feet (18 m) wide by 449 feet (137 m) long.[17]

The four-story Launch Control Center was located 3.5 miles (5.6 km) away from Pad A, adjacent to the Vehicle Assembly Building for safety. The third floor had four firing rooms (corresponding to the four high bays in the VAB), each with 470 sets of control and monitoring equipment.[when?] The second floor contained telemetry, tracking, instrumentation, and data reduction computing equipment. The LCC was connected to the Mobile Launchers by a high speed data link, and during launch a system of 62 closed-circuit television cameras transmitted to 100 monitor screens in the LCC.[17]

Large cryogenic tanks located near the pads stored the liquid hydrogen and liquid oxygen (LOX) for the second and third stages of the Saturn V. The highly explosive nature of these chemicals required numerous safety measures at the Launch Complex. The pads were located 8,730 feet (2,660 m) away from each other.[17] Before tanking operations began and during launch, non-essential personnel were excluded from the danger area.

Each pad had a 200-foot (61 m) evacuation tube running from the Mobile Launcher platform to a blast-resistant bunker 39 feet (12 m) underground, equipped with survival supplies for 20 persons for 24 hours. There was also a cab/slidewire system running from the 322-foot (98 m) tower level to evacuate astronauts and technicians 2,503 feet (763 m) away from the pad.[20]

Connections between the Launch Control Center, mobile launcher platform and space vehicle are made in the Pad Terminal Connection Room (PTCR). The facility was a two-story series of rooms beneath the launch pad, constructed of reinforced concrete located on the west side of the flame trench and was protected by up to 20 feet (6.1 m) of fill dirt.[21][22]

The first use of LC-39 came in 1967 with the first Saturn V launch, carrying the unmanned Apollo 4 spacecraft. The second unmanned launch, Apollo 6, also used Pad 39A. With the exception of Apollo 10, which used Pad 39B (due to the "all-up" testing resulting in a 2-month turnaround period), all manned Apollo-Saturn V launches, commencing with Apollo 8, used Pad 39A.

A total of thirteen Saturn Vs were launched for Apollo, and the unmanned launch of the Skylab space station in 1973. The mobile launchers were then modified for the shorter Saturn IB rockets, by adding a "milk-stool" extension platform to the launch pedestal, so that the S-IVB upper stage and Apollo spacecraft swing arms would reach. These were used for three manned Skylab flights and the Apollo-Soyuz Test Project, since the Saturn IB pads 34 and 37 at Cape Canaveral AFB had been decommissioned.[23][24]

The thrust to allow the Space Shuttle to achieve orbit was provided by a combination of the Solid Rocket Boosters (SRBs) and the Space Shuttle Main Engines (SSMEs). The SRBs used solid propellant, hence their name. The SSMEs used a combination of liquid hydrogen and liquid oxygen (LOX) from the External Tank (ET), as the orbiter did not have internal fuel tanks for the SSMEs (as they would be have had to be as large as the External Tank). The SRBs arrived in segments via rail car from their manufacturing facility in Utah, the External Tank arrived from its manufacturing facility in Louisiana by barge, and the orbiter waited in the Orbiter Processing Facility (OPF). The SRBs were first stacked in the VAB, and then the External Tank was mounted between them. Then, using a massive crane, the orbiter was lowered and connected to the External Tank.

Payload to be installed at the launch pad was independently transported in a payload transportation canister then installed vertically at the Payload Changeout Room. Otherwise, payloads would have already been pre-installed at the Orbiter Processing Facility and transported within the orbiter's cargo bay.

The original structure of the pads was remodeled for the needs of the Space Shuttle, starting with Pad 39A after the last Saturn V launch, and in 1977 for Pad 39B after the Apollo-Soyuz Test Project in 1975.

Columbia standing on pad 39A, ready for its first orbital flight (STS-1, April 1981). The Rotating Service Structure has been rolled away in preparation for launch.

Each pad contained a two-piece access tower system, the Fixed Service Structure (FSS) and the Rotating Service Structure (RSS). The FSS permitted access to the Shuttle via a retractable arm and a "beanie cap" to capture vented LOX from the External Tank. The RSS contained the Payload Changeout Room, which offered "clean" access to the orbiter's payload bay, protection from the elements, and protection in winds up to 60 knots (110 km/h).

A Sound Suppression Water System (SSWS) was added to protect the Space Shuttle and its payload from effects of the intense sound wave pressure generated by its engines. An elevated water tank on a 290-foot (88 m) tower near each pad stored 300,000 gallons (1.1 Megalitres) of water, which was released onto the Mobile Launcher Platform just before engine ignition.[25] The water muffled the intense sound waves produced by the engines. Due to heating of the water, a large quantity of steam was produced during launch.

The doors to the White Room, which provided entry to the Shuttle crew compartment, are seen here at the end of the access arm walkway

The Gaseous Oxygen Vent Arm positioned a hood, often called the "Beanie Cap," over the top of the External Tank (ET) nose cone during fueling.[when?] Heated gaseous nitrogen was used there to remove the extremely cold gaseous oxygen that normally vented out of the External Tank. This prevented the formation of ice that could fall and damage the shuttle.[26]

The Hydrogen Vent Line Access Arm mated the External Tank (ET) Ground Umbilical Carrier Plate (GUCP) to the launch pad hydrogen vent line. The GUCP provided support for plumbing and cables, called umbilicals, that transferred fluids, gases, and electrical signals between two pieces of equipment. While the ET was being fueled, hazardous gas was vented from an internal hydrogen tank through the GUCP, out a vent line to a flare stack where it was burned off at a safe distance. Sensors at the GUCP measured gas level. The GUCP was redesigned after leaks created scrubs of STS-127 and were also detected during attempts to launch STS-119 and STS-133.[27] The GUCP released from the ET at launch and fell away with a curtain of water sprayed across it for protection from flames.

In an emergency, the launch complex used a slidewire escape basket system for quick evacuation. Assisted by members of the closeout team, the crew would leave the orbiter and ride an emergency basket to the ground at speeds reaching up to 55 miles per hour (89 km/h).[28] From there, the crew took shelter in a bunker. A modified M113 Armored Personnel Carrier could carry injured astronauts away from the complex to safety.[29]

During the launch of Discovery on STS-124 on May 31, 2008, the pad at LC-39A suffered extensive damage, in particular to the concrete trench used to deflect the SRB's flames.[30] The subsequent mishap investigation found that the damage was the result of carbonation of epoxy and corrosion of steel anchors which held the refractory bricks in the trench in place. These had been exacerbated by the fact that hydrochloric acid is an exhaust by-product of the solid rocket boosters.[31]

After the launch of Skylab in 1973, Pad 39A was reconfigured for the Space Shuttle, with shuttle launches beginning in 1981 with STS-1, flown by the Space ShuttleColumbia.[32] After Apollo 10, Pad 39B was kept as a backup launch facility in the case of the destruction of 39A, but saw service for all three Skylab missions, the Apollo-Soyuz test flight, and a contingency Skylab Rescue flight that never became necessary. After the Apollo-Soyuz Test Project, 39B was reconfigured similarly to 39A, but due to additional modifications (mainly to allow the facility to service a modified Centaur-G upper stage), along with budgetary restraints, it was not ready until 1986, and the first shuttle flight to use it was STS-51-L, which ended with the Challenger disaster. The first return to flight mission STS-26 launched from 39B.

The last Shuttle launch from Pad 39B was the nighttime launch of STS-116 on December 9, 2006. To support the final Shuttle mission to the Hubble Space Telescope STS-125 launched from Pad 39A in May 2009, Endeavour was placed on 39B if needed to launch the STS-400 rescue mission.

After the completion of STS-125, 39B was converted for the single test flight of the Constellation ProgramAres I-X from Pad 39B on October 28, 2009.[33]

With the retirement of the Shuttle in 2011,[34] and the cancellation of Constellation Program in 2010, the future of the LC-39 pads was uncertain. By early 2011, NASA began informal discussions on use of the pads and facilities by private companies to fly missions for the commercial space market,[35] culminating in a 20-year lease agreement with SpaceX for Pad 39A.[36]

Just like the first 24 shuttle flights, Pad 39A supported the final manifested shuttle flights, starting with STS-117 in June 2007 until the retirement of the shuttle fleet in July 2011. Prior to the SpaceX lease agreement, the pad remained as it was when Atlantis launched on the final shuttle mission on July 8, 2011, complete with a mobile launcher platform.

By early 2013, NASA publicly announced that it would allow commercial launch providers to lease Pad 39A,[38] and followed that, in May 2013, with a formal solicitation for proposals for commercial use of Launch Pad 39A.[39] There were two competing bids for the commercial use of the launch complex.[40]SpaceX submitted a bid for exclusive use of the launch complex, while Jeff Bezos' Blue Origin submitted a bid for shared non-exclusive use of the complex such that the launchpad would interface with multiple vehicles, and costs could be shared over the long term. One potential shared user in the Blue Origin plan was United Launch Alliance.[41] Prior to completion of the bid period, and prior to any public announcement by NASA of the results of the process, Blue Origin filed a protest with the U.S.General Accounting Office (GAO) "over what it says is a plan by NASA to award an exclusive commercial lease to SpaceX for use of mothballed space shuttle launch pad 39A."[42] NASA had planned to complete the bid award and have the pad transferred by October 1, 2013, but the protest "will delay any decision until the GAO reaches a decision, expected by mid-December."[42] On December 12, 2013, the GAO denied the protest and sided with NASA, which argued that the solicitation contains no preference on the use of the facility as multi-use or single-use. "The [solicitation] document merely asks bidders to explain their reasons for selecting one approach instead of the other and how they would manage the facility."[43]

In 2015, SpaceX built a large Horizontal Integration Facility (HIF) just outside the perimeter of the existing launch pad in order to house both the Falcon 9, and the Falcon Heavy, rockets, and their associated hardware and payloads, during preparation for flight.[50] Both types of launch vehicles will be transported from the HIF to the launch pad aboard a Transporter Erector (TE) which will ride on rails up the former Crawlerway path.[37][50] Also in 2015, the launch mount for the Falcon Heavy was constructed on Pad 39A over the existing infrastructure.[51][52] The work on both the HIF building, and the pad, were substantially complete by late 2015.[53] A rollout test of the new Transporter/Erector (TE) was conducted in November 2015.[54]

SpaceX indicated in February 2016 that they had "completed and activated Launch Complex 39A",[55] but still has more work yet to do to support crewed flights. SpaceX originally planned to be ready to accomplish the first launch at pad 39A — a Falcon Heavy — as early as 2015,[48] as they had architects and engineers working on the new design and modifications since 2013.[56][51] By late 2014, a preliminary date for a wet dress rehearsal of the Falcon Heavy was set for no earlier than July 1, 2015.[37] Due to a failure in a June 2015 Falcon 9 launch, SpaceX had to delay launching the Falcon Heavy in order to focus on the Falcon 9's failure investigation and its return to flight.[57] In early 2016, considering the busy Falcon 9 launch manifest, it became unclear if Falcon Heavy would be the first vehicle to launch from Pad 39A, or if one or more Falcon 9 missions would precede a Falcon Heavy launch.[55]

The first SpaceX launch from pad 39A was SpaceX CRS-10 using a Falcon 9 on February 19, 2017; it was the company's 10th cargo resupply mission to the International Space Station,[58] and the first unmanned launch from 39A since Skylab.

As a result of ongoing reconstruction at SLC-40 after the loss of the AMOS-6 satellite, all SpaceX's east coast launches are being launched from LC-39A until SLC-40 is back to operational status (currently scheduled for sometime in the summer of 2017). On May 1, 2017, NROL-76 was the first SpaceX mission for the National Reconnaissance Office with a classified payload.[59]

SpaceX intends to utilize the Fixed Service Structure (FSS) of the Pad 39A launch towers, and will extend it above its existing 350-foot (110 m) height, but will not need the Rotating Service Structure (RSS) and will remove it. Initial plans in 2014 called for leaving the RSS in place until after the first Falcon Heavy launch;[37] however, plans were changed, and work on RSS takedown began in February 2016.[62] NASA has already removed the Orbiter Servicing Arm and white room by which astronauts entered the Space Shuttle.[51] SpaceX indicated in late 2014 that no additional levels to the FSS would be added in the near term.[37] SpaceX plans to later add at least two additional levels to the FSS, and will utilize the FSS for providing crew access for the Dragon V2 launches.[63] Launch vehicles will be assembled horizontally in a hangar near the pad, transferred to the pad, and then lifted atop a launch platform for the remainder of the launch prep and lift off.[56] For military missions from Pad 39A, payloads will be vertically integrated, as that is required per launch contract with the US Air Force.[56] A hammerhead crane will be added to the FSS in order to support US military requirements for vertical payload integration.[63]

Pad 39A will be used to host launches of astronauts on the crewed-version of the Dragon space capsule in a public–private partnership with NASA. The NASA plan as of April 2014[update] calls for the first NASA crewed missions in 2017.[56] SpaceX intends to add "a crew gantry access arm and white room to allow for crew and cargo ingress to the vehicle. The existing Space Shuttle evacuation slide-wire basket system will also be re-purposed to provide a safe emergency egress for the Dragon crew in the event of an emergency on the pad that does not necessitate using the Crew Dragon’s launch abort system."[64]

Since the Ares I-X flight, NASA proceeded with plans to strip Pad 39B of its Flight Service Structure (FSS), returning the location to an Apollo-like "clean pad" design for the first time since 1977. This approach will make the pad available to multiple types of vehicles which arrive at the pad with service structures on the mobile launcher platform as opposed to custom structures on the pad.[65] The LH2, LOX, and water tanks (used for the sound suppression system) are the only structures left from the Space Shuttle era.[66][67][68]

As of June 2012[update], repairs and modifications to selected facility systems at Launch Complex (LC) 39B for Space Launch System (SLS) processing and launch operations are finishing the first phase of a five-phase project. The second phase of this project is currently budgeted at $89.2 million ($6.1 million in FY 2012, $28.5 million in FY 2013, $9.4 million in FY 2014 and $45.2 million in the outyears).[69][needs update] In March 2015, Pad 39B was undergoing modifications to the Catacomb Roof structure so that it can handle the loads from the SLS Block 1B rocket, increasing the load capacity to support the crawler-transporter and vertical rocket from 21,000,000 to 25,500,000 pounds (9,500,000 to 11,600,000 kg).[66]

In 2014, NASA announced that it would make Pad 39B available to commercial users during times when it is not needed by the Space Launch System.[56] As of May 2017[update], NASA has one SLS mission scheduled in 2019, and a second one in 2021.[56]

Construction of the pad began in January 2015 and was completed in June 2015. Kennedy Space Center Director Robert D. Cabana and representatives from the Ground Systems Development and Operations (GSDO) Program and the Center Planning and Development (CPD) and Engineering Directorates marked the completion of the new pad during a ribbon-cutting ceremony July 17, 2015.

"As America's premier spaceport, we're always looking for new and innovative ways to meet America's launch needs, and one area that was missing was small class payloads," Robert D. Cabana said. "Using 21st Century funds, we built Pad 39C."[8]

GSDO oversaw the project and is working with CPD to grow commercial space efforts at Kennedy.[8]

"Pad 39C is the latest addition to our portfolio of launch pads," said Scott Colloredo, CPD director. "The small class market is here. The demand for that kind of launcher is increasing. The key here is this is really what a launch site for a small class launcher needs to look like."[8]

The concrete pad measures about 50 feet (15 m) wide by about 100 feet (30 m) long and could support the combined weight of a fueled launch vehicle, payload and customer-provided launch mount up to about 132,000 pounds (60,000 kg), and an umbilical tower structure, fluid lines, cables and umbilical arms weighing up to about 47,000 pounds (21,000 kg).[8]

GSDO also developed a universal propellant servicing system to provide liquid oxygen and liquid methane fueling capabilities for a variety of small class rockets.[8]

"This is absolutely great to designate a new pad within the confines of Pad 39B. I'm looking forward to having customers here in the not too distant future, making use of this outstanding facility," Robert D. Cabana said[8]

KSC’s newest Launch Pad, designated 39C, is designed to accommodate Small Class Vehicles. Located in the southeast area of the Launch Complex 39B perimeter, this new concrete pad measures about 50 feet (15 m) wide by about 100 feet (30 m) long. Launch Complex 39C will serve as a multi-purpose site allowing companies to test vehicles and capabilities in the smaller class of rockets, making it more affordable for smaller companies to break into the commercial spaceflight market.

As part of this capability, NASA’s Ground Systems Development and Operations Program developed a universal propellant servicing system, which can provide liquid oxygen and liquid methane fueling capabilities for a variety of small class rockets. This system is slated for operational readiness in the summer of 2016.[8]

With the addition of Launch Complex 39C, KSC can offer the following processing and launching features for companies working with small class vehicles (maximum thrust up to 200,000 pounds-force (890 kN)):[70]

^Dean, James (2011-02-06). "Up for grabs? Private companies eye KSC facilities". Florida Today. Retrieved 2011-02-06. As the shuttle program nears retirement, KSC officials are evaluating whether other facilities that supported three decades of shuttle flights will transition to serve new vehicles or be discarded. The center is offering use of its launch pads, runway, Vehicle Assembly Building high bays, hangars and firing rooms to private companies expected to play a bigger role in NASA missions and a growing commercial space market.